Este trabajo fue financiado por los Institutos Nacionales de Salud (R01DK58096 a Vincent Poitout). Vincent Poitout titular de la Cátedra de Investigación de Canadá en la diabetes y la función pancreática de las células beta. Bader Zarrouki recibido becas post-doctorales de Merck y Eli Lilly. Fontes Ghislaine fue apoyado por una beca post-doctoral de la Asociación Canadiense de Diabetes.

Descripción general: El procedimiento consiste en la cateterización de la vena yugular derecha y la arteria carótida izquierda bajo anestesia general; permitiendo un período de recuperación de 7 días; conexión de los catéteres de las bombas utilizando un eslabón giratorio y el sistema de contrapeso que permite que el animal se mueva libremente en la jaula; y la infusión de la glucosa y / o Intralipid (una emulsión de aceite de soja que genera una mezcla de aproximadamente 80% unsaturated/20% de ácidos grasos saturados con infusión de heparina 9) durante 72 horas. 1. Canulación de la vena yugular derecha y la arteria carótida izquierda <ol><li> Esterilizar los instrumentos quirúrgicos. Tubo de canulación también debe ser esterilizada en frío utilizando un agente esterilizante líquido (2,6% de glutaraldehído) antes del procedimiento. Sumerja el tubo en un recipiente esterilizado en autoclave durante 16-24 horas. Aclarar y lavar con agua destilada estéril para eliminar todos los rastros de glutaraldehído antes de su uso. </li><li> Pesar la rata para calculardosis de los fármacos: El carprofeno 5 mg / kg: dilución 1/10 = Peso corporal (g) x 0.001 ml SC (analgésico) Glycopyrrolate 0,01 mg / kg: dilución 1/10 = BW (g) X 0,0012 ml en SC (anticolinérgico) </li><li> Anestesiar la rata utilizando isoflurano y oxígeno. </li><li> Coloque la rata en su estómago. Afeitar el área detrás de las orejas a la base de los hombros. Coloque la rata en la espalda. Afeitarse la región bajo el cuello de las patas delanteras. </li><li> Preparación del sitio quirúrgico con clorhexidina, alcohol, y yodo. Administrar medicamentos. </li><li> Transferir la rata para el campo quirúrgico. </li><li> Utilizando una técnica aséptica, canulate la vena yugular derecha y la arteria carótida izquierda con un PE-50 cánula unida a una jeringa de 1 ml llena con 5 U de solución salina heparinizada. Lave las cánulas con 50 U de solución salina heparinizada para evitar la formación de coágulos durante el período de recuperación. Usar agujas 23G romos. Cierre cada cánula con un pasador de 23G. </li><li> Después de la cirugía, recorte de aproximadamente 2,5 mm de laincisivos inferiores y coloque la rata en una chaqueta de infusión para evitar que las cánulas de ser comido. </li><li> Proporcionar oxígeno (1 L / min durante 10 min) para ayudar a evacuar isoflurano. </li><li> Coloque la rata en una jaula caliente hasta que esté completamente despierto. </li><li> Utilice cuatro ratas de utilizar uno por condiciones infusión (tabla 1). </li></ol> 2. Cuidados después de la operación (Tratamiento post-quirúrgico y de conexión de los catéteres) <ol><li> Pese a las ratas en el día 1 y el día 2 después de la cirugía. </li><li> Administrar glycopyrrolate (BW (g) x 0,00048 ml) SC dos veces en el día 1 después de la cirugía y una vez en el día 2 después de la cirugía. </li><li> Tratamientos de apoyo adicionales se pueden administrar si es necesario: líquidos, el cojín de la calefacción, la dieta húmeda, oxigenoterapia, analgésicos, anticolinérgicos. </li><li> En el día 7 después de la cirugía, las ratas pesan para calcular las tasas de flujo de infusión. </li><li> Conectar cada rata para un sistema de infusión usando una correa de sujeción y giratorio montado en una tapa de parrilla de jaula (Figura 1).</li><li> Lave las cánulas con 5 U de solución salina heparinizada para eliminar los coágulos. Lave las cánulas una vez más con 50 U de solución salina heparinizada para evitar la coagulación. </li><li> Permitir que las ratas se aclimaten a la correa de sujeción y giro para por lo menos 24 horas antes de comenzar la infusión. </li></ol> 3. Infusión <ol><li> Dibuje 0,15 ml de sangre de la carótida de cada rata y medida de la glucemia. Lave las cánulas yugulares. Usa 50 U de solución salina heparinizada para prevenir la coagulación en ambas cánulas de cada rata. </li><li> Transferir la muestra de sangre a un tubo de recogida de 0,5 ml que contiene 2% de EDTA. Centrifugar a 10.000 rpm durante 2 min y congelar el plasma a -20 ° C. </li><li> Llenar dos jeringas de 60 ml para cada una de las condiciones de infusión se enumeran a continuación. Jeringa 1 Place de la posición frente a la bomba de jeringa y 2 º lugar en la posición posterior de la bomba. </li><li> Une cada par de soluciones junto con Y-conectores y tubos T22 CO-EX que ha sido esterilizado. Coloque las jeringas en un 33 Harvardbomba de jeringa doble. </li><li> Cambiar el fondo de la jaula y retire todos los alimentos de la parrilla superior jaula. </li><li> Pesar 150 g de pienso estándar y colocar en la parrilla superior jaula. </li><li> Conecte la jeringa a la pieza giratoria en la parrilla jaula. Lave las jeringas adecuadamente para eliminar el aire atrapado en las líneas. </li><li> Calcular las tasas de flujo de infusión utilizando el peso corporal que se tomó antes de conectar la rata para el sistema de infusión. Las tarifas se calculan con un archivo de Microsoft Excel que convierte la tasa de infusión de glucosa (GIR) en ml / h. </li><li> Coloque la bomba para administrar los caudales de jeringas 60 ml de acuerdo a la configuración del fabricante. Introduzca el tipo de jeringa 1 (jeringa frontal) y la tasa de Jeringa 2 (back jeringa). </li><li> Encienda la bomba. </li></ol> 4. Monitoreo <ol><li> Después de arrancar la bomba, compruebe que no hay fugas de la pieza giratoria o de las cánulas y el tubo de infusión que no está torcido. Compruebe también que no haya burbujas de aire enel tubo. </li><li> Después de 3 horas de la infusión, tomar una muestra de sangre para controlar la glucemia. Repita después de 6, 24, 48 y 72 h de infusión. Como medida de precaución, la glucemia también se controla después de 30, 34, 54 y 60 h de la infusión. La glucosa en sangre se puede medir usando una gota de sangre entera usando un monitor de glucosa portátil. Esto limita la cantidad de sangre extraída durante la infusión y por lo tanto evita alterar de manera significativa el volumen de sangre y / o el hematocrito. </li><li> La tasa para la jeringa 1 se modifica en función de los valores de glucemia para mantener la glucosa en la sangre 220-250 mg / dl. La tasa de jeringa 2 no cambia durante la hora 72 de infusión porque los ácidos grasos libres se mantienen a 1 mmol / L. </li><li> Condiciones de infusión están emparejados de manera que el volumen recibido por los animales de control es equivalente al volumen recibido por los animales de ensayo (Tabla 1). </li><li> Después de 24 horas de la infusión, cambiar el fondo de la jaula y se pesa la comida que queda en la parrilla de la jaula. Devuelve la parte no consumido to La parrilla de jaula. Repita después de 48 horas. </li><li> Jeringas Recarga día según sea necesario durante la hora 72 de la infusión. </li><li> Durante la infusión, respete siempre las ratas para detectar cualquier signo de inflamación o malestar. Administrar la atención adecuada si es necesario. </li></ol> 5. La eutanasia después de la infusión <ol><li class="jove_content"> Después de 72 horas de la infusión, las ratas se anestesiaron por vía intravenosa con 0,5 ml de un cóctel de ketamina / xilazina (182 mg / kg de ketamina y 11,6 mg / kg de xilazina diluyó 1:2 con 0,9% de NaCl). </li><li class="jove_content"> El reflejo del dedo del pie-pellizco se utiliza para verificar el nivel de anestesia. Anestésico adicional se administra según sea necesario. </li><li class="jove_content"> Cuando la rata es anestesiada, la cavidad abdominal se abrió con unas tijeras quirúrgicas. La rata se desangraron mediante la elaboración 10-15 ml de sangre en una jeringa de la aorta o la vena cava. </li></ol>

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C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+glucose+stimulates+early+response+gene+c-Myc+expression+in+rat+pancreatic+beta+cells.">High glucose stimulates early response gene c-Myc expression in rat pancreatic beta cells.</a> The Journal of Biological Chemistry. 276, 35375-35381 (2001).</li><li>Tang, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glucose-induced+beta+cell+dysfunction+in+vivo+in+rats:+link+between+oxidative+stress+and+endoplasmic+reticulum+stress.">Glucose-induced beta cell dysfunction in vivo in rats: link between oxidative stress and endoplasmic reticulum stress.</a> Diabetologia. 55, 1366-1379 (2012).</li><li>Alonso, L. 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Vincent Poitout es co-fundador de y recibió contratos de investigación de Bêtagenex Inc., una organización de investigación por contrato que ofrece el modelo de infusión se presenta en este artículo como un servicio comercial.

Aunque un número de estudios previos han empleado infusiones crónicas de la glucosa (por ejemplo, 10-15) o lípidos (por ejemplo, 16,17) en roedores, a nuestro conocimiento la infusión combinada de ambos combustibles sólo se ha informado en ratones 18. El modelo de infusión crónica presentado aquí ofrece varias ventajas para el estudio de los efectos sobre el exceso de nutrientes en una variedad de funciones biológicas en las ratas. En primer lugar, no se trata ...

Se han propuesto los niveles crónicamente elevados de glucosa y lípidos en la circulación de contribuir a la patogénesis de la diabetes tipo 2 mediante la alteración de la función de varios órganos implicados en el mantenimiento de la homeostasis de la glucosa, incluyendo, pero no limitado a, la células beta pancreáticas (revisado en 1). Las hipótesis postula que la hiperglucemia crónica glucotoxicidad agrava el defecto de las células beta, que dio lugar a la hiperglucemia, en primer lugar, creando así un círculo vicioso y contribuyendo al deterioro del control glucémico en pacientes con diabetes tipo 2. Del mismo modo, la hipótesis glucolipotoxicity propone que las elevaciones concomitantes de los niveles de glucosa y de los lípidos, como a menudo se observan en la diabetes tipo 2, son perjudiciales para la célula beta. Descifrar los mecanismos celulares y moleculares de los efectos deletéreos de nutrientes crónicamente elevados sobre la función de las células beta pancreáticas es la clave para la understanding de la patogénesis de la diabetes tipo 1 2. Para ello, un gran número de estudios han examinado los mecanismos de exceso de nutrientes crónica ex vivo en islotes aislados de Langerhans o in vitro, en líneas celulares secretoras de insulina clonales. Sin embargo, la traducción de los resultados obtenidos en estos sistemas modelo para todo el organismo es compleja, en particular debido a que las concentraciones de ácidos grasos utilizados en células cultivadas o islotes raramente coinciden con los niveles circulantes en la vecindad de las células beta in vivo 2. Por otro lado, los mecanismos de fallo de las células beta en respuesta al exceso de nutrientes se han examinado en modelos de roedores de la diabetes, como se ejemplifica en la rata Zucker Diabetic Fatty 3,4, el jerbo Psammomys obesus 5 y la dieta alta en grasas- alimentados ratón 6. Estos modelos, sin embargo, se caracterizan por anormalidades metabólicas intrínsecas y no son fácilmente susceptibles a las manipulaciones de la glucosa en sangrey / o los niveles de lípidos en un entorno más controlado y menos crónica. Para ser capaz de alterar los niveles circulantes de nutrientes en un plazo de días en los animales por lo demás normales, hemos desarrollado un modelo de infusión crónica en ratas normales que nos permite examinar los efectos de los lípidos y la glucosa, solo o en combinación, sobre los parámetros y la función fisiológica 7,8.

<table border="1">
		<tbody>
		 <tr>
			<td>Name of Reagent/Material</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		 </tr>
		 <tr>
			<td>Saline 0.9%</td>
			<td>BD</td>
			<td>JB1324</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Dextrose 70%</td>
			<td>McKesson</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Intralipid 20%</td>
			<td>Fresenius Kabi</td>
			<td>JB6023</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Metricide (Glutaraldehyde 2.6%)</td>
			<td>Metrex</td>
			<td>11-1401</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Heparin Sodium 10,000 USP u/ml</td>
			<td>PPC</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Carprofen</td>
			<td>Metacam</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Glycopyrrolate</td>
			<td>Sandoz</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Isoflurane</td>
			<td>Abbott</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Chlohexidine 2%</td>
			<td></td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Alcohol 70%</td>
			<td></td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Iodine</td>
			<td></td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>PE-50</td>
			<td>BD</td>
			<td>427411</td>
			<td></td>
		 </tr>
		 <tr>
			<td>CO-EX T22</td>
			<td>Instech Solomon</td>
			<td>BCOEX-T22</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Connector 22G</td>
			<td>Instech Solomon</td>
			<td>SC22/15</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Swivel 22G</td>
			<td>Instech Solomon</td>
			<td>375/22PS</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Y-Connector 22G</td>
			<td>Instech Solomon</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Counterbalance and arm</td>
			<td>Instech Solomon</td>
			<td>CM375BP</td>
			<td></td>
		 </tr>
		 <tr>
			<td>23 G blunted needles</td>
			<td>Instech Solomon</td>
			<td>LS23</td>
			<td></td>
		 </tr>
		 <tr>
			<td>23 G canulation pins</td>
			<td>Instech Solomon</td>
			<td>SP23/12</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Tethers (12 inch)</td>
			<td>Lomir</td>
			<td>RT12D</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Infusion jackets </td>
			<td>Lomir</td>
			<td>RJ01, RJ02, RJ03, RJ04</td>
			<td></td>
		 </tr>
		 <tr>
			<td>(SM-XL)</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Tether attachment piece</td>
			<td>Lomir</td>
			<td>RS T1</td>
			<td></td>
		 </tr>
		 <tr>
			<td>60 ml syringe</td>
			<td>BD</td>
			<td>309653</td>
			<td></td>
		 </tr>
		 <tr>
			<td>1 ml syringe</td>
			<td>BD</td>
			<td>309602</td>
			<td></td>
		 </tr>
		</tbody>
 </table>

a model of chronic nutrient infusion in the rat

Se postula la exposición crónica a niveles excesivos de nutrientes para afectar a la función de varios órganos y tejidos y para contribuir al desarrollo de las muchas complicaciones asociadas con la obesidad y el síndrome metabólico, incluyendo la diabetes de tipo 2. Para el estudio de los mecanismos por los que los niveles excesivos de glucosa y ácidos grasos afectan a la células beta pancreáticas y la secreción de la insulina, hemos establecido un modelo de infusión de nutrientes crónica en la rata. El procedimiento consiste en la cateterización de la vena yugular derecha y la arteria carótida izquierda bajo anestesia general; permitiendo un período de recuperación de 7 días, la conexión de los catéteres de las bombas utilizando un eslabón giratorio y el sistema de contrapeso que permite que el animal se mueva libremente en la jaula, y la infusión glucosa y / o Intralipid (una emulsión de aceite de soja que genera una mezcla de aproximadamente 80% unsaturated/20% de ácidos grasos saturados con infusión de heparina) durante 72 h. Este modelo ofrece varias AdvantaGES, incluyendo la posibilidad de modular finamente los niveles objetivo de glucosa y ácidos grasos circulantes; la opción de co-infundir compuestos farmacológicos, y el marco de tiempo relativamente corto en comparación con los modelos dietéticos. Puede ser utilizado para examinar los mecanismos de la disfunción de nutrientes inducida en una variedad de órganos y para probar la eficacia de los fármacos en este contexto.

De una serie de 42 ratas a las que se sometieron a cirugía, 5 ratas se perdieron durante el período post-operatorio y 1 rata se perdió durante la infusión, lo que representa una tasa de éxito del 86%. El peso promedio de las 37 ratas que fueron finalmente infunden fue 608 ± 5 g antes de la cirugía y 588 ± 6 g al inicio de la infusión (media ± SE, n = 37, p &lt;0,0001 en la prueba t pareada). Se obtuvieron los siguientes resultados representativos en 2 grupos de infusión de solución salina.: (SAL), y la Gluco...

Watch this Scientific Journal Video about A Model of Chronic Nutrient Infusion in the Rat at JoVE.com

A Model of Chronic Nutrient Infusion in the Rat

Se describe un protocolo para infusiones de glucosa y crónicas Intralipid en ratas. Este modelo puede ser utilizado para estudiar el impacto del exceso de nutrientes en la función del órgano y los parámetros fisiológicos.

Un modelo de infusión de nutrientes crónica en la rata

Chronic exposure to excessive levels of nutrients is postulated to  affect the function of several organs and tissues and to contribute to the  ...

a-model-of-chronic-nutrient-infusion-in-the-rat

Research

JoVE Journal

Medicine

12.6K vistas.  CRCHUM. Se describe un protocolo para infusiones de glucosa y crónicas Intralipid en ratas. Este modelo puede ser utilizado para estudiar el impacto del exceso de nutrientes en la función del órgano y los parámetros fisiológicos.

Video: A Model of Chronic Nutrient Infusion in the Rat

Orthotopic Aortic Transplantation: A Rat Model to Study the Development of Chronic Vasculopathy

Research models of chronic rejection are essential to investigate pathobiological and pathophysiological processes during the development of transplant vasculopathy (TVP).
The commonly used animal model for cardiovascular chronic rejection studies is the heterotopic heart transplant model performed in laboratory rodents. This model is used widely in experiments since Ono and Lindsey (3) published their technique. To analyze the findings in the blood vessels, the heart has to be sectioned and all vessels have to be measured.
Another method to investigate chronic rejection in cardiovascular questionings is the aortic transplant model (1, 2). In the orthotopic aortic transplant model, the aorta can easily be histologically evaluated (2). The PVG-to-ACI model is especially useful for CAV studies, since acute vascular rejection is not a major confounding factor and Cyclosporin A (CsA) treatment does not prevent the development of CAV, similar to what we find in the clinical setting (4). A7-day period of CsA is required in this model to prevent acute rejection and to achieve long-term survival with the development of TVP.
This model can also be used to investigate acute cellular rejection and media necrosis in xenogeneic models (5).

This video demonstrates the orthotopic aortic transplant model as a simple model to study the development of transplant vasculopathy (TVP) in rats.

Trasplante ortotópico aórtica: un modelo de rata para estudiar el desarrollo de la enfermedad vascular crónica

Research models of chronic rejection are essential to investigate pathobiological and pathophysiological processes during the development of transplant ...

Investigación

Medicina

Urinary Bladder Distention Evoked Visceromotor Responses as a Model for Bladder Pain in Mice

Approximately 3-8 million people in the United States suffer from interstitial cystitis/bladder pain syndrome (IC/BPS), a debilitating condition characterized by increased urgency and frequency of urination, as well as nocturia and general pelvic pain, especially upon bladder filling or voiding. Despite years of research, the cause of IC/BPS remains elusive and treatment strategies are unable to provide complete relief to patients. In order to study nervous system contributions to the condition, many animal models have been developed to mimic the pain and symptoms associated with IC/BPS. One such murine model is urinary bladder distension (UBD). In this model, compressed air of a specific pressure is delivered to the bladder of a lightly anesthetized animal over a set period of time. Throughout the procedure, wires in the superior oblique abdominal muscles record electrical activity from the muscle. This activity is known as the visceromotor response (VMR) and is a reliable and reproducible measure of nociception. Here, we describe the steps necessary to perform this technique in mice including surgical manipulations, physiological recording, and data analysis. With the use of this model, the coordination between primary sensory neurons, spinal cord secondary afferents, and higher central nervous system areas involved in bladder pain can be unraveled. This basic science knowledge can then be clinically translated to treat patients suffering from IC/BPS.

Approximately 3-8 million people in the United States suffer from interstitial cystitis/bladder pain syndrome (IC/BPS), a debilitating condition characterized in part by pelvic pain. In order to study nervous system contributions to the condition, a physiological model of urinary bladder pain is used in mice and rats.

Las respuestas de la Vejiga Urinaria Distensión Evocados visceromotor como modelo para la vejiga Dolor en ratones

Approximately 3-8 million people in the United States suffer from interstitial cystitis/bladder pain syndrome (IC/BPS), a debilitating condition ...

Slow-release Drug Delivery through Elvax 40W to the Rat Retina: Implications for the Treatment of Chronic Conditions

Diseases of the retina are difficult to treat as the retina lies deep within the eye. Invasive methods of drug delivery are often needed to treat these diseases. Chronic retinal diseases such as retinal oedema or neovascularization usually require multiple intraocular injections to effectively treat the condition. However, the risks associated with these injections increase with repeated delivery of the drug. Therefore, alternative delivery methods need to be established in order to minimize the risks of reinjection. Several other investigations have developed methods to deliver drugs over extended time, through materials capable of releasing chemicals slowly into the eye. In this investigation, we outline the use of Elvax 40W, a copolymer resin, to act as a vehicle for drug delivery to the adult rat retina. The resin is made and loaded with the drug. The drug-resin complex is then implanted into the vitreous cavity, where it will slowly release the drug over time. This method was tested using 2-amino-4-phosphonobutyrate (APB), a glutamate analogue that blocks the light response of the retina. It was demonstrated that the APB was slowly released from the resin, and was able to block the retinal response by 7 days after implantation. This indicates that slow-release drug delivery using this copolymer resin is effective for treating the retina, and could be used therapeutically with further testing.

This paper details how Elvax 40W can be used as a slow-release method for drug delivery to the adult rat retina. The protocol for preparing, loading, and delivering the drug-resin complex to the eye is described.

De liberación lenta Drug Delivery través Elvax 40W a la Rata Retina: Implicaciones para el tratamiento de condiciones crónicas

Diseases of the retina are difficult to treat as the retina lies deep within the eye. Invasive methods of drug delivery are often needed to treat these ...

Neurodegeneration in an Animal Model of Chronic Amyloid-beta Oligomer Infusion Is Counteracted by Antibody Treatment Infused with Osmotic Pumps

Decline in hippocampal-dependent explicit memory (memory for facts and events) is one of the earliest clinical symptom of Alzheimer&#39;s disease (AD). It is well established that synapse loss and ensuing neurodegeneration are the best predictors for memory impairments in AD. Latest studies have emphasized the neurotoxic role of soluble amyloid-beta oligomers (A&#946;o) that begin to accumulate in the human brain approximately 10 to 15 yr before the clinical symptoms become apparent. Many reports indicate that soluble A&#946;o correlate with memory deficits in AD models and humans. The A&#946;o-induced neurodegeneration observed in neuronal and brain slice cultures has been more challenging to reproduce in many animal models. The model of repeated A&#946;o infusions shown here overcome this issue and allow addressing two key domains for developing new disease modifying therapies: identify biological markers to diagnose early AD, and determine the molecular mechanisms underpinning A&#946;o-induced memory deficits at the onset of AD. Since soluble A&#946;o aggregate relatively fast into insoluble A&#946; fibrils that correlate poorly with the clinical state of patients, soluble A&#946;o are prepared freshly and injected once per day during six days to produce marked cell death in the hippocampus. We used cannula specially design for simultaneous infusions of A&#946;o and continuous infusion of A&#946;o antibody (6E10) in the hippocampus using osmotic pumps. This innovative in vivo method can now be used in preclinical studies to validate the efficiency of new AD therapies that might prevent the deposition and neurotoxicity of A&#946;o in pre-dementia patients.

To study the effects of A&#946;o in vivo, we developed a model based on repeated hippocampal infusions of soluble A&#946;o coupled with continuous infusion of A&#946;o antibody (6E10) in the hippocampus using osmotic pumps to counteract the neurotoxic effect of A&#946;o.

Neurodegeneración en un modelo animal de beta-amiloide crónica Oligómero de infusión es contrarrestado por el anticuerpo Tratamiento Con una infusión de bombas osmóticas

Decline in hippocampal-dependent explicit memory (memory for facts and events) is one of the earliest clinical symptom of Alzheimer&#39;s disease (AD). It ...

Use of a Central Venous Line for Fluids, Drugs and Nutrient Administration in a Mouse Model of Critical Illness

This protocol describes a centrally catheterized mouse model of prolonged critical illness. We combine the cecal ligation and puncture method to induce sepsis with the use of a central venous line for fluids, drugs and nutrient administration to mimic the human clinical setting. Critically ill patients require intensive medical support in order to survive. While the majority of patients will recover within a few days, about a quarter of the patients need prolonged intensive care and are at high risk of dying from non-resolving multiple organ failure. Furthermore, the prolonged phase of critical illness is hallmarked by profound muscle weakness, and endocrine and metabolic changes, of which the pathogenesis is currently incompletely understood. The most widely used animal model in critical care research is the cecal ligation and puncture model to induce sepsis. This is a very reproducible model, with acute inflammatory and hemodynamic changes similar to human sepsis, which is designed to study the acute phase of critical illness. However, this model is hallmarked by a high lethality, which is different from the clinical human situation, and is not developed to study the prolonged phase of critical illness. Therefore, we adapted the technique by placing a central venous catheter in the jugular vein allowing us to administer clinically relevant supportive care, to better mimic the human clinical situation of critical illness. This mouse model requires an extensive surgical procedure and daily intensive care of the animals, but it results in a relevant model of the acute and prolonged phase of critical illness.

This protocol describes a centrally catheterized mouse model of prolonged critical illness. We combine the cecal ligation and puncture method to induce sepsis with the use of a central venous line for fluids, drugs and nutrient administration to mimic the human clinical setting.

El uso de una línea venosa central para fluidos, Drogas y Administración de nutrientes en un modelo de ratón de la enfermedad crítica

This protocol describes a centrally catheterized mouse model of prolonged critical illness. We combine the cecal ligation and puncture method to induce ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

Medición de la contractilidad isométrica de la arteria mesentérica de ratón con cable miografía

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

A New Best Practice for Validating Tail Vein Injections in Rat with Near-infrared-Labeled Agents

Intravenous (IV) administration of agents into the tail vein of rats can be both difficult and inconsistent. Optimizing tail vein injections is a key part of many experimental procedures where reagents need to be introduced directly into the bloodstream. Unwittingly, the injection can be subcutaneous, possibly altering the scientific outcomes. Utilizing a nanoemulsion-based biological probe with an incorporated near-infrared fluorescent (NIRF) dye, this method offers the capability of imaging a successful tail vein injection in vivo. With the use of a NIRF imager, images are taken before and after the injection of the agent. An acceptable IV injection is then qualitatively or quantitatively determined based on the intensity of the NIRF signal at the site of injection.

Here we present a method to validate tail vein injections in rats by utilizing near-infrared fluorescence imaging data from dyes incorporated into agents or biological probes. The tail is imaged before and after the injection, the fluorescent signal is quantified, and an assessment of the injection quality is made.

Una mejor práctica para la validación de las inyecciones de vena de cola en rata con agentes cerca infrarrojo-marcado con

Intravenous (IV) administration of agents into the tail vein of rats can be both difficult and inconsistent. Optimizing tail vein injections is a key part ...

Acupuncture in a Rat Model of Asthma

A high platform can fix rats without restriction and completely expose the acupoints on the back during acupuncture manipulation. This article describes methods for the fabrication of the high platform, establishes a rat model of asthma and measures changes in respiratory function using a noninvasive and real-time whole-body plethysmography (WBP) system.

Acupuntura en un modelo de rata de asma

A high platform can fix rats without restriction and completely expose the acupoints on the back during acupuncture manipulation. This article describes ...

A Mouse Model for Chronic Pancreatitis via Bile Duct TNBS Infusion

Chronic pancreatitis (CP) is a complex disease involving pancreatic inflammation and fibrosis, glandular atrophy, abdominal pain and other symptoms. Several rodent models have been developed to study CP, of which the bile duct 2,4,6 -trinitrobenzene sulfonic acid (TNBS) infusion model replicates the features of neuropathic pain seen in CP. However, bile duct drug infusion in mice is technically challenging. This protocol demonstrates the procedure of bile duct TNBS infusion for generation of a CP mouse model. TNBS was infused into the pancreas through the ampulla of Vater in the duodenum. This protocol optimized drug volume, surgical techniques, and drug handling during the procedure. TNBS-treated mice showed features of CP as reflected by bodyweight and pancreas weight reductions, changes in pain-associated behaviors, and abnormal pancreatic morphology. With these improvements, mortality associated with TNBS injection was minimal. This procedure is not only critical in generating pancreatic disease models but is also useful in local pancreatic drug delivery.

Chronic pancreatitis (CP) is a disease characterized by inflammation and fibrosis of the pancreas, often associated with intractable abdominal pain. This article focuses on refining the technique to generate a mouse model of CP via bile duct infusion with 2,4,6 -trinitrobenzene sulfonic acid (TNBS).

Un modelo de ratón para la pancreatitis crónica a través de la infusión de TNBS del conducto biliar

Chronic pancreatitis (CP) is a complex disease involving pancreatic inflammation and fibrosis, glandular atrophy, abdominal pain and other symptoms. ...

Mejora de la terapia con FSN en el modelo de rata: minimización de las molestias y maximización de la eficiencia

Efficacy of Fu's Subcutaneous Needling on Sciatic Nerve Pain: Behavioral and Electrophysiological Changes in a Chronic Constriction Injury Rat Model

Fu&#39;s subcutaneous needling (FSN), an invented acupuncture technique from traditional Chinese medicine, is used worldwide for pain relief. However, the mechanisms of action are still not fully understood. During FSN treatment, the FSN needle is inserted and retained in the subcutaneous tissues for a long duration with a swaying movement. However, challenges arise from maintaining a posture while manipulating FSN in animal models (e.g., rats) for researchers. Uncomfortable treatment can lead to fear and resistance to FSN needles, increasing the risk of injury and may even affect research data. Anesthesia may also affect the study results too. Hence, there is a need for strategies in FSN therapy on animals that minimize injury during the intervention. This study employs a chronic constriction injury model in Sprague-Dawley rats to induce neuropathic pain. This model replicates the pain induced by nerve injury observed in humans through surgical constriction of a peripheral nerve, mimicking the compression or entrapment seen in conditions such as nerve compression syndromes and peripheral neuropathies. We introduce an appropriate manipulation for easily inserting an FSN needle into the subcutaneous layer of the animal&#39;s body, including needle insertion and direction, needle retention, and swaying movement. Minimizing the rat&#39;s discomfort prevents the rat from being tense, which causes the muscle to contract and hinder the entry of the needle and improves the study efficiency.

Autor destacado: Desvelando los efectos terapéuticos del tratamiento con FSN: uniendo la investigación y las aplicaciones clínicas en el dolor neuropático

We present a protocol for using Fu's subcutaneous needling in a chronic constriction injury model to induce sciatic nerve pain in rats.

Eficacia de la punción subcutánea de Fu en el dolor del nervio ciático: cambios conductuales y electrofisiológicos en un modelo de rata con lesión por constricción crónica

Fu&#39;s subcutaneous needling (FSN), an invented acupuncture technique from traditional Chinese medicine, is used worldwide for pain relief. However, the ...